1. Field of the Invention
The present invention relates to a method and system for coexistence between wireless communication networks which coexist in a communication space by time division or frequency division among a plurality of wireless communication networks.
2. Description of the Related Art
In recent years, the number of subscriptions in a wireless communication system has increased, or the advancement and diversity of a service has been developed. In this case, when a plurality of wireless communication networks coexist in the same communication space and the same frequency band, the wireless communication networks cause communication interference in each other. As a result, a method for coexistence between the wireless communication networks which coexist in a communication space by time division or frequency division among the plurality of wireless communication networks has been required from the related art.
For example, in a method for coexistence in the communication space by time division among the plurality of wireless communication networks, a time frame constituted by a plurality of time slots is divided into several time slot groups, and the divided time slot groups are allocated to respective systems.
Further, in a method for coexistence in the communication space by frequency division among the plurality of wireless communication networks, a predetermined frequency band is divided into two or more partial frequency bands, and the divided partial frequency bands are allocated to respective systems.
As the method for coexistence between the wireless communication networks in the related art, for example, methods illustrated in U.S. Pat. No. 5,732,076 and US Patent Application No. 2008/247,445 are proposed.
FIG. 10 illustrates a general example in which communication interference between a wireless communication network 61 and another network occurs. In this example, the wireless communication network 61 includes a device 72 based on a channel A and a coordinator 71 controlling the entire network. In this case, other wireless communication networks 62 and 63 of which communication spaces overlap with the wireless communication network 61 exist. Communication interference between the wireless communication network 62 and the wireless communication network 61 caused by using the channel A, similarly as the wireless communication network 61. In this regard, communication interference between the wireless communication network 63 and the wireless communication network 61 using the channel A does not occur since the wireless communication network 63 uses channel B.
A wireless communication network 64 uses the channel A, similarly as the wireless communication network 61, but communication interference does not particularly occur since the wireless communication network 64 uses a communication space different from the wireless communication network 61.
That is, the communication space overlaps with the wireless communication network 61 and interference occurs between the wireless communication network 64 and other wireless communication network 62 using a common channel.